Fuse



June 6, 1933- H. R. COOK 1-: AL

FUSE

Filed May 20, 1930 livan 1 )(rbcrf Fay 00010, E nest J1 Bo d/ w Patented June 6, 1933 UNITED STATES PATENT OFFICE HERBER-T RAY COOK AND ERNEST A. BOHLMAN, CHICAGO, ILLINOIS, ASSIGNORS TO JEFFERSON ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, I A CORPORATION 01 ILLINOIS FUSE Application filed May 20. 1930. serial in. 454,188.

. More particularly the invention relates to a renewable ferrule type of fuse, the general object being to provide a new and improved fuse of this character, simple and rugged in construction and efficient in operation.

Another object is to provide a new and improved ferrule fuse which is economical in construction and comprises parts which are readily assembled.

Another objectis to provide an improved fuse embodying a novel means for attaching 1 metal ferrules to a tubular insulating casing adapted effectively to secure the ferrules to the casing against rotational or longitudinal movement.

Another object isto provide aferrule fuse comprising an insulating casing and a pair of metal ferrules rigidly secured to the ends of the casing in a manner such that they will not loosen due to changes in the fiber casing caused by atmospheric conditions or by the forces exerted upon the blowing of a fusible element.

A further object is to provide a novel end,

construction for ferrule fuses having eflicient and rigidly supported clamping means for the fusible element.

Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawing, in which:

Figure 1 is a view partly" in longitudinal central section of the preferred form of the invention.

Fig. 2 is a perspective view of the fuse showing the parts disassembled.

Fig. 3 is an end view of a modified form of ferrule and bridge member.

Fig. 4 is a section along the line 'l4.- of Fig. 3.

For purposes of disclosure we have illustrated in the drawing and shall hereinafter describe in detail the preferred embodiment of the invention with the understanding that we do not intend to limit our invention to the particular construction and arrangement shown, it being contemplated that various changes may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

As illustrated in the drawing, the invention in the exemplary form chosen for .purposes of disclosure comprises a tubular casing' 1 of suitable insulating material, the ends of which are turned down or otherwise reduced to a smaller diameter as at 2 to receive metal ferrules 3. Annular grooves 4 are formed in the casing at the inner end of the reduced portions 2, these grooves or recesses having end walls in lanes substantially transverse to the axis 0 the casing providing opposing shoulders 5 and 6. The internal surfaces of the ferrules 3 are smooth so as to fit snugly over the reduced portions 2 of, the casing.

In the exemplary form of the invention the ferrules are provided-with transversely extending end walls 7 having apertures 8 therethrough provided with a straight side 9. The ferrules are shown positioned upon thecasing so that the straight sides 9 of the ferrules on the twoeends will be parallel but with the apertures 8 oppositely disposed and means is provided for positioning the ferrules in such alinement and for securing each ferrule against rotation relative to the easing. This means is preferably in the form of devices, one at each end of the casing, which devices are connected to the casing by means preventing relative rotation therebetween and are also connected to the for rule by means preventing relative rotation therebetween. As disclosed herein, the ends -of the casing are provided with pairs of diametrically opposed slots 10 arranged, to receive portions or prongs 11 on a pair of such devices in the form of somewhat semi-circular bridge members or plates 12. The plates12 are preferably positioned extending transversely of the ends of the casing with the prongs 11 fitting snugly into the slots 10 so as effectively to prevent relative rotation between the plates and the casing.

The means for connecting the members 12 to the ferrules may assume various forms. two of which are disclosed herein. Thus as illustrated in Figs. 1 and 2, the members 12 are provided with eccentrically disposed re cesses 13 which are adapted to receive and interengage with lugs 14 punched inwardly from the end wall 7 of the ferrules. The engagement of the lugs 14 in the recesses 13 and that of the prongs 11 in the slots effectively prevent rotational movement of the ferrules on the casing, the interengaging parts being located so that when the parts are assembled and the ferrules are secured to the casing the straight edges 9 of the end apertures 8 will be oppositely positioned and parallel.

The ferrules are secured to the casing against longitudinal movement in a manner ads ted to resist effectively the large forces ten ing to blow the end structures off of the casing when a fusible element is disrupted, As illustrated herein the ferrules are slipped as far as they will go over the reduced portions 2 of the casing, with the intermediate bridge plates 12 properly pesitioned therebetween, and are then secured to the casing by lei-shaped ribs 15 crimped or rolled there- This crimping operation bends portions of the ferrules around end into engagement with the shoulders This together with the abutment of the end walls of the ferrules uinst the bridge plstes prevents movement -.e ferrules longitudinally of the casing. El is actually drawn into ded ngeinst the opens. 6- so as to leave the e shoulders in comprese shoulders 6 tension.

y sewith threaded e cups stop short euros leave portions l9 dismeter which fit someireuded end portions 9/9 of the As illustrated herein, washers .21 are positioned intermediate the inner walls of l e end caps and the bent over ends the 'iusible element. In order to ventilate the fuse and prevent a direct discharge of the gases upon the blowing of a fusible element, these washers are preferably spaced from the inner wall of the end cap by means of a plurality of inwardly punched lugs 22 and are provided with a plurality of peripherally spaced recesses 23 which connect the chamber so formed with the interior of the casing. A passage for the expanding gases is therefore provided extending through the apertures 8, between the end walls 7 of the ferrules and the plates 21, through the recesses 23, and between the plates 21 and the inner end walls of the caps to vent 24 positioned centrally in the caps.

By providing metallic members such as the bridge members 12 for locking the ferrules to the casing against rotation, the ferrules are not only held effectively to the casing but furthermore the end walls 7 thereof are reinforced against dishing when the end caps are ti htened to clamp the fusible element. Pre erubly the bridge members are formed so that the straight sides thereof coincide with the straight sides 9 of the ferrule end apertures to obtain this reinforcing effect. It is epperent that with the slots 10 in the casing and the integral prongs 11 on the bridge members relative rotation therebetween is prevented and similarly by the engagement of the integral lugs 14 on the ferrules with the recesses 13 in the bridge members relative rotation therebetween is elso prevented. In addition, the provision of such means for preventing relative rotation of the members permits the parts to be independently ferr ed and yet insures perfect ulinement of the 0 .rule operlure sides 9 by :1 simple assembly of the and Well b ing sufhciently ti:

use 92, nd cup return u ,3 i. r one Ween 1 on. Herengu. 111g of 1', lx u t e fuse c .i means is .W lv nunzeu by lacing the lugs 22 111 ly from "e effecof the teens path guides .1 side while of the cups so as tively to en vrt the central per the same time a tor washers. At is provided for the gases which v z tne gases around the washers and along the end walls of the end caps to cool the and prevent any direct discharge 0 gases from the casing.

In Fl 5. 3 and 4 we have shown a modified form 0 ferruleand bridge member. As illustrated a ferrule 25 is rovided with a transverse end wall 26 having a fuse aper ture 27 therethrough and a relatively small eccentricslly positioned recess 28. A bridge member 29 is provided having prongs 30 which are ada ted to engage the slots in the casing. Wit this form of construc tion the bridge member is preferably rigidly or permanently attached to the ferrule as by riveting. As shown in the drawing the end wall of the bridge member is proases hot the bri vided with an outwardly punched lug 31 which is adapted to extend through the recess 28. After the bridge member is so positioned the end of the lug 31 is bent or riveted as at 32 so as to secure the bridge member to the ferrule. assembly of the bridge member and ferrule separate from the casing and secures them rigidly together so that there will be no tendenc for the interengaging portions of d g'e member and ferrule to disengage should the parts tend to become loose upon shrinkage of the fiber tube, and effectively prevents rotation of the ferrule relatively to the casing.

We claim as our invention;

1. In aferrule fuse, in combination, a tubular casing of insulating material hav ing an end portion of reduced diameter and an annular recess in said end portion, the end of said casing having a slot therein, a

. substantially semicircular bridge member extending transversely across the end of the casing and having a p0rt1on entering said slot to prevent relatlve rotary move- 7 ment therebetween, a ferrule arranged to slip snugly over said end portion and having an apertured end wall abutting said bridge member, and means to prevent relative rotary movement between said ferrule and bridge member comprising a portion of one part engaging in a recess of the other, said ferrule-having a U-shaped rib crimped thereon positioned in the annular recess of the casing to secure the ferrule against longitudinal movement relatively to the-cas- 1n g In a ferrule fuse, in combination, a. tubular casing of insulating material having an end portion of reduced diameter and an annular recess in said end portion providing opposing shoulders, a ferrule ar-- ranged to slip snugly over said end portion and having an apertured end wall and means coacting with the end wall of ,the ferrule and easing arranged to prevent relative rotary movement therebetween, said ferrule having a U-shaped rib crimped thereon positioned in the annular recess of the casing and abutting the two shoulders formed thereby to secure the ferrule against longitudinal movement relatively to the casing.

3. In a ferrule fuse, in' combination, a tubular casing of insulating material having an end portion of reduced diameter and an annular recess in said end portion, a bridge member abutting the end of the casing, means to prevent relatively rotary movement between the bridge member ,and casing, and a ferrule arranged to slip snugly over said end portion and having an apertured end wallabutting said bridge mem ber, means to prevent relative rotary move- 11 ant between the ferrule and bridge member, said ferrule having a rib crimped there- This permits of tudinal movement relatively tothe casing.

4. In a ferrule fuse, in combination, a tubular casing of insulating material having an end portion of reduced diameter and an annular recess in said end portion, a ferrule arranged to slip over said end portion, a metallic member adjacent the end of the casing arranged to prevent relative rotary movement between the ferrule and casing, said ferrule having a portion thereof positioned in the annular recess of the casing to secure the ferrule against longitudinal movement relatively to the casing.

5. A ferrule fuse comprising, in combination, a tubular easing of insulating'material having a slot in each end thereof, a pair of ferrules arranged to fit over the end portions of the casing and having. apertured end walls extending transversely of the easing, means to secure said ferrules to'the casing, a fusible element extending through the casing and ferrules having its ends bent over against the end walls of the ferrules, means to clamp said fusible element a ainst the end walls of the ferrules, a pair 0' members interposed between the ends of the casing and the walls of the ferrules to reinforce the end walls on one side of the apertures th'erehaving a pair of diametrically opposed slots in each end thereof, a pair of ferrules arranged to fit over the end portions of the casing and having apertured end walls extending transversely of the casing, means to secure said ferrules to the casing, a fusible element extending through the casing and ferrules having its ends bent over against the end walls of the ferrules, means to clamp said fusible elementagainst the ferrules and a pair of substantially semi-circular bridge members interposed between the ends of the casing and the walls of the ferrules and in abutment therewith to reinforce the ferrules on one side of the apertures therein.

7. A ferrule fuse comprising, in combination, a tubular casing of insulating material, a pair of ferrules arranged to fit over the end portions of the casing and having apercasing,.means to secure said ferrules to the 'casing, a fusible element extending through of bridge members interposed between the ends of the casing and the walls of the ferrules to reinforce the end walls.

'tured end walls extending transversely of the 8. In a fuse, in combination, a tubular casing of insulating material, a pair of metallic ferrules secured to the opposite ends of said casing and having apertured end walls through. which a fusible element ma project, a fusible element extendingthroug the casing and having its ends overlapping said end walls, and means to clamp sai fusible element to the ferrules comprising a pair of end caps having screw threaded engagement with the ferrules and vent apertures in the end walls thereof and a pair of washers respectively positioned in said caps and bearing against the bent over ends of the fusible element and the end walls of the caps, said end caps having a plurality of lugs integral with and pressed inwardly from the end walls thereof to directly engage and space said washers and reinforce the central portions thereof, the gas passing to said vent apertures around the peripheries of said washers.

9. In a fuse, in combination, a tubular casing of insulating material having an end portion ofreduced diameter and an annular recess in said end portion rectangular in Y cross-section to provide opposed shoulders,

a ferrule arranged to slip over said end portion, said ferrule having an annular rib rectangular in cross-section positioned in the annular recess of the casing and abutting the two shoulders formed thereby to secure the ferrule against longitudinal movement and means to prevent relative rotary movement between the ferrule and casing.

10. In a ferrule fuse, in combination, a tubular casing of insulating material having end portions of reduced diameter and recesses in said end portions providing shoulders, ferrules arranged to slip over said end portions, said ferrules having end walls preventing movement of the ferrules in one direction longitudinally of the casing and having portions pressed inwardly and into engagement with said shoulders to prevent longitudinal movement of the ferrule in the opposite direction on the casing, and metallic members coacting with the end walls of said ferrules and the casing arranged to prevent relative rotary movement between the ferrules and casing.

11. In a ferrule fuse, in combination, a tubular casing of insulating material having an end portion of reduced diameter with a pair of end slots therein, a ferrule arranged to slip over said end portion, means to secure the ferrule to the casing against longitudinal movement and means to prevent relative rotary movement between the ferrule and easing including a bridge member extending "transversely across the end of the casing and having a pair of longitudinally extending prongs fitting in said slots.

12. In a ferrule fuse, in combination, a

tubular casing of insulating material having a slot in one end thereof, a ferrule arranged to sli over the end of the casing having said s ot, means to secure the ferrule to the casing against longitudinal movement and means to prevent relative rotary movement between the ferrule and easing comprising a member extending transversely of the easing having a portion fitting in said slot and means to secure said member to said ferrule arrangedto prevent relative rotation therebetween.

13.'In a ferrule fuse, in combination, a tubular casing of insulating material having a slot in one end thereof, a ferrule arranged to slip over said end of the casing, means to secure the ferrule to the casing against longitudinal movement and means to prevent relative rotary movement between the ferrule andcasing com rising a member extending transversely o the casing having a prong fitting in said slot and interengaging means on said member and said ferrule arranged to prevent relative rotation therebetween.

14. In a ferrule fuse, in combination, a tubular casing of insulating material having a slot in one end thereof, a ferrule arranged to slip over the end of the casing having said slot, means to secure the ferrule to the easing against longitudinal movement and means to prevent relative rotary movement between the ferrule and casing comprising a member extending transversely of the casing having a prong fitting in said slot and means to prevent relative rotation between said member and said ferrule.

15. In a ferrule fuse, in combination, a tubular casing, a fusible element extending through said casing and means to secure said element in said casing including an end cap having a transverse integral wall closing the end of the casing and provided with a centrally disposed vent aperture, a single washer positioned within said end cap spaced from said end wall and arranged to bear against said element and a plurality of lugs pressed inwardly from and integral with the end wall of said ca and directly bearing against said washer or spacing said washer from said end wall and reinforcing the central portion thereof, the gas passing around the periphery of said washer to said vent aperture.

In testimony whereof we have hereunto afiixed our signatures.

HERBERT RAY COOK. ERNEST A. BOHLMAN. 

